coeliac disease- general overview

Coeliac disease

Coeliac disease or gluten-sensitive enteropathy is a state of heightened immunological responsiveness to ingested gluten in genetically susceptible individuals.

Epidemiology

Coeliac disease is a disease of Europe and occurs in populations of European migration (America, Australia). The prevalence varies by location and stage of diagnosis (symptomatic disease, asymptomatic seropositive disease and genetic predisposition), a concept known as the coeliac iceberg .In the UK, the prevalence of endomysial antibody positive patients is 1200 per 100 000 (1.2%). Coeliac disease is twice as common in females, and presentation in adulthood (typically the fourth to sixth decade) is now more common than in childhood.

Pathology

There is a strong genetic component to coeliac disease: almost all patients are either HLA DQ2 or DQ8 positive), and 15% of first-degree relatives may be affected.

Gluten is a high molecular weight heterogeneous compound found in the endosperm (white flour portion) of wheat, rye and barley. In patients with coeliac disease, the ingestion of gluten results in an immunological response and causes small bowel inflammation. Raised antibody titres in untreated coeliac disease include gliadin, reticulin, endomysium and tissue transglutaminase.

The histological features of coeliac disease are classified in concordance with the revised Marsh criteria and tend to be more severe in the duodenum and jejunum, possibly due to greater proximal gluten load.

Associated disease
Prevalence of coeliac disease
Family history ( first degree relatives )
5-15%
Type 1 Diabetes
3-5 %
Autoimmune thyroid disease
3-8 %
Selective IgA deficiency
2-5%
Irritable bowel syndrome
3-5%
Primary biliary cirrhosis
3%
Female infertility
3%
Osteoperosis
3%

Scope of disease

Patients with unrecognized coeliac disease can have nutritional deficiencies of iron (iron deficiency anaemia), vitamin B12 or folate. Up to 60% may have reduced bone mineral density (osteoporosis or osteopenia) due to inadequate calcium absorption. Most complications are avoidable or reversible on a gluten-free diet.

Patients with coeliac disease have a higher risk of gastrointestinal malignancy (small bowel lymphoma). There is also an association with splenic aplasia and other autoimmune diseases.

Clinical features

Patients with coeliac disease may be asymptomatic (silent) or present with atypical symptoms (atypical form). The median delay from the onset of symptoms to diagnosis is approximately 5 years.

The classic symptoms of coeliac disease occur soon after the introduction of wheat cereals into infant feed. Children present with soft, clay-coloured, bulky and offensive stool, resulting from steatorrhoea. Malabsorption results in failure to thrive, anorexia and muscle wasting. Diarrhoea and abdominal pain occasionally occur.

In adults, the mode of presentation is varied with non-specific symptoms of diarrhoea, abdominal pain, bloating, nausea and vomiting. Alternative presentations relate to the complications of glossitis, anaemia, osteoporosis, bleeding diathesis (vitamin K deficiency), weight loss and dermatitis herpetiformis.

On examination, patients may be of short stature from chronic malnutrition. Anaemia may be evident, as may koilonychia from iron deficiency. There may be stomatitis and a blistering pruritic symmetrical skin rash on the elbows, knees, scalp, face, neck and sacral areas (dermatitis herpetiformis). Abdominal examination may reveal ascites from hypoproteinaemia.

Initial investigations

The most important investigational aspect of coeliac disease is a high index of suspicion.

Full blood count and blood film.

Anaemia may be present with target cells and Howell-Jolly bodies on the blood film.

Serological markers

The profile of antibodies requested consists of endomysial, tissue transglutaminase and antigliadin antibodies (IgG and IgA). Endomysial and tissue transglutaminase are specific investigations, however IgA and IgG antigliadin antibodies are more sensitive in less severe disease (partial or subtotal villous atrophy) and in patients with concurrent IgA deficiency (where endomysial, tissue transglutaminase and IgG antigliadin antibodies may be negative).

Further investigations

Duodenal biopsy

The diagnosis is confirmed by performing gastroscopy and duodenal biopsy. Prior to undertaking a duodenal biopsy, blood should be screened for coagulation abnormalities that could result from vitamin K deficiency.

Haematinic studies

Further studies for iron, B12 and red cell folate levels will be required in patients with anaemia to characterize the aetiology. Bone marrow aspiration may be required in selected patients with megaloblastic anaemia.

DEXA scan

A bone mineral density scan is required to screen for osteopenia in patients with confirmed disease.

Screening for gastrointestinal lymphoma

Patients with persistent symptoms despite compliance with a gluten-free diet should be screened for small bowel lymphoma using enteroscopy (deeper endoscopic viewing of the small bowel), and gastrointestinal video capsule endoscopy.

Initial management

Education

Patients should be educated about their disease and encouraged to join national support groups for information and advice such as Coeliac UK ( and Celiac.com . They should also be counselled about the possible complications and the risk of coeliac disease in their first-degree relatives.

Diet

The cornerstone of management for coeliac disease is a gluten-free diet, and referral to a dietician is mandatory. The removal of gluten from the diet may result in complete resolution of symptoms, improvement of nutritional deficiencies and avoidance of complications. Duodenal biopsies may be repeated 3-6 months after commencement on a gluten-free diet to assess for evidence of histological improvement.

Nutritional supplementation

Dietary supplementation is required for iron and folate deficient patients. Regular B12 injections may be required for B12 deficiency, although serum levels often improve with a gluten-free diet. Calcium supplementation is required for patients with osteopenia, especially postmenopausal women.

Pneumococcal vaccination

Pneumococcal vaccination is recommended due to the association of coeliac disease with splenic atrophy, although the benefit remains to be proven.

Medical management

Immunosuppression

In general, long-term steroids are not indicated unless there is persistent severe hypoalbuminaemia to regain control of a protein-losing enteropathic state. Corticosteroids are usually reserved for the treatment of coeliac crisis, characterized by severe malabsorption (diarrhoea, weight loss, ascites and hypoproteinaemia). This condition is now rarely seen as antibody testing means that patients are often recognized at an earlier stage in the disease process. The management of refractory coeliac disease (without lymphoma) may require both corticosteroids and other immunosuppressants (azathioprine and anti-TNF antibody).

Surgical management

The role of surgery is limited and confined to refractory coeliac disease with lymphomatous change or when overt lymphoma develops, when surgical resection may be required.

Prognosis

The mortality of patients with coeliac disease is modestly increased compared to controls, with an overall hazard ratio for death of 1.17. The risk of gastrointestinal and haematological malignancies is also increased (gastrointestinal lymphoma occurs in approximately 6% and manifests in the sixth decade).

Symptom control is generally good as long as patients are compliant and adhere to a gluten-free diet. The less compliance with a gluten-free diet, the greater is the likelihood of the development of complications.

Screening

There is no accepted screening programme for coeliac disease. There is currently controversy on whether population screening should be provided, given that the prevalence may be as high as 1%.


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Cresentmoon2007 5 years ago from Caledonia, MI

Interesting and well informative. Voted up.

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